Extrude Cut

Introduction

This topic will explain the Extrude Cut function, will explain where to find the function, and explain the options found in it. This topic will also give a brief description of Dynamic Drawing, the Snap Increment function, explain creation with quick steps and an example, and provide links to related topics.

The Extrude Cut Function

The Extrude Cut function removes material from solid bodies by extruding closed wireframe chains or planar surface geometry to the specified distance and subtracts the result from any intersecting solid or surface bodies. When using a surface, the software automatically extracts the edges of the surface to use for the cut.

 

Important: By default, Extrude Cut is applied to all intersecting bodies in the file, unless they are hidden using the Blank function in the document toolbar, or the Selected Bodies option is used to specify the bodies to interact with.Without the Selected Bodies option, hiding a layer does not exclude the entities on that layer from being affected by the Extrude Cut.

 

Dynamic Drawing

This function supports Dynamic Drawing which allows you to use a combination of sketching and data entry to create the entities. Prior to confirming the desired result in the function, an adjustable preview is visible. These previews can be modified using the sketch handles, data entry, or a combination of both. The benefit of Dynamic Drawing is that you can quickly place and adjust the size to get the approximate result, and then use data entry to update to the exact dimensions, and coordinate values as needed.

 

Preview with Sketch Handles	Final Entities

 

In the images above, we see the preview of entities which can be adjust with sketch handles, followed by those same entities after they are finalized.

Snap Increment

This function support the use of the snap increment when selecting the location of the entities. The snap increment allows you to get precise results when using mouse selection and helps to reduce data entry modifications.

 

To learn more, view Snap Increment.

Navigation

To open Extrude Boss:

• In the Extrude group, of the Create 3D tab, click Extrude Cut.

 

The parameters display in the Data Entry Manager.

The Data Entry Parameters

Selected Geometry

	(Delete) - removes the highlighted item from the Selected Geometry list. (Delete All) - removes all entities from the Selected Geometry list.
The list will display all entities currently selected for the function.

 

 

 

 

Scope

 

• All Bodies - With this option selected, all intersecting solid bodies not set to a Blank state will be affected by this feature. This includes bodies on layers set to a hidden state.
  
  

• Selected Bodies - With this option selected, only those intersecting solid bodies added to the selected geometry list below will be affected by this feature.

 

Selected Geometry

	(Delete) - removes the highlighted item from the list. (Delete All)- removes all entities from the list.
This list box will show the entities currently selected for the function.

 

• OK - finalizes the function.
  
  
• Cancel - exits the function.

Quick Steps - Extrude Cut

 

Start		Finish

 

1. Open the function and define all Data Entry parameters.
   
   

2. Select geometry in the graphics area.
   
   This can sometimes be made easier by pressing S to turn off the shaded view, as seen below.
   
   
   
   The geometry can be closed wireframe chains, surface edges, or planar surface geometry. When using a surface, the software automatically extracts the edges of the surface to use for the boss.
   
   With geometry selected, the preview appears.
   
   
   
   

3. Use the dynamic sketch handles, with or without snap increment, and/or data entry to update the CAD preview as needed.
   
    
   
   

4. Leave the Scope set to All Bodies, and click OK to confirm.
   
   
   
   The feature is added to the CAD Tree.
   
   

5. Click Cancel to close the function.

Example

A BobCAD file installed with the software can be opened to follow along with this example.

 

In the example file, Extrude Cut is used to cut a hole through the center of a solid flange.

 

Part 1) Open the Example File

1. In the Quick Access Toolbar, click Open.
   
   

2. Navigate to: C:\BobCAD-CAM Data\BobCAD-CAM V**\Examples, and select ExtrudeCut Example.bbcd.
   
   

3. With Extrude Cut Example.bbcd displaying in the File Name box, click Open.

Part 2) Open Extrude Cut

To open Extrude Cut:

• In the Extrude group, of the Create 3D tab, click Extrude Cut.

 

The parameters display in the Data Entry Manager.

Part 3) Create an Extruded Cut

When using Extrude Cut, you can select closed wireframe chains or planar surface geometry. For this example, we select a wireframe chain and then explore Dynamic Drawing to define the extrusion direction and distance from the chain.

 

1. Press S,or select Shaded from the document toolbar.
   
   The Shading is removed from the model.
   
   
   
   

2. Under the graphics area, change the value of the (Snap Increment) to 0.2500.
   
   This allows us to sketch CAD sizes and depths in increments of 0.2500.
   
   

3. For this example, we select the geometry first before defining the Data Entry parameters. This way we can create the CAD preview and explore Dynamic Drawing.
   
   In the graphics area, hover over the circle, as seen in the image below.
   
   
   
   

4. Click the arc to add it to the Selected Geometry list.
   
   The Preview appears.
   
   

 

Note: Notice that by default the circle is extruded one unit in the positive direction. For any Extrude function, you can specify the extrude distance in either or both directions from the selected geometry. You can also apply a Draft Angle to either or both directions.

 

5. To show how Dynamic Drawing works, hover over the sketch handle as seen in the image below.
   
   
   
   

6. Click the sketch handle to activate it.
   
   The sketch handle highlights and the preview moves down based on the next snap increment.
   

 

Note: When a sketch handle is activated, the CAD preview changes to a wireframe display until you place the sketch handle. Move the handle down and notice it does not move smoothly, but jumps by an incremental amount. This is the snap increment amount that has been set. Notice too, that the Other Direction Distance is updating as the sketch handle is being moved.

 

7.  Move the sketch handle so that the Other Direction Distance is set to 3.0000.
   
   
   
   

8. Click to set the sketch handle.
   
   The Preview updates.
   
   
   
   

9. To perform the Extrude Cut, leave the Scope set to All Bodies, and click OK.
   
   The Extrude Boss is created in the graphics area and another Extrude Cut feature is created in the CAD Tree.
   
   
   
   

10. Press S, or select Shaded from the document toolbar.
    
    The Shading appears on the model.
    
    
    
    

11. To close the Data Entry Manager, click Cancel.

 

The process of creating an Extrude Cut is complete. The rest of this example provides some important usage tips.

Part 4) Excluding Solids from Extrude Cut

It is important to understand when using the All Bodies option is that any solid body in the file that intersects the extruded shape is included in the Extrude Cut result. This applies to all visible or hidden solids unlessthey are hidden using the Blank command, found in the document toolbar. When set to All Bodies, hiding a CAD layer does not exclude the solids on that layer.

 

1. In the Layer Manager, click the Layers tab if it isn't already selected.
   
   

2. In the Layers Manager, right-click the layer name Flange Copy, and click Show.
   
   If needed, rotate the view to see that the second flange was also cut, even though it was on a hidden CAD layer.

 

 

If the second flange was hidden using Blank, it would not have been included in the Extrude Cut.

 

Tip: After hiding a solid using Blank in order to exclude it from an Extrude Cut, or Boss and then showing the solid using Unblank, if the CAD Tree is rebuilt, that solid will then be included in the Extrude Cut result. If this creates a problem, you can use Solid Subtract instead of Extrude Cut.

 

For this example we didn't want to cut the second flange. This problem is easily resolved by editing the Extrude Cut feature.

Part 5) The CAD Tree

One CAD feature is added to the CAD Tree each time you perform Extrude Cut. The feature in the CAD Tree provides many tools for editing, suppressing, renaming the feature, and more as explained in the CAD Tree.

 

After closing the Data Entry Manager, the CAD Tree automatically displays. You can also click the in the CAD Tree Manager to access the CAD Tree.

 

1. Notice the Extrude Cut feature at the bottom of the CAD Tree.
   
   Double-click Extrude Cut to edit it.
   
   The CAD preview displays, and the Extrude Cut Parameters open in the Data Entry Manager.
   
   
   
   

2. In the Scope section, select Selected Bodies.
   
   The Selected Geometry list appears.
   
   

3. Select the intended body.
   
   
   
   The body is added to the Selected Geometry list.
   
   

4. To finish editing the feature, click OK.
   
   
   
   The feature is updated with the copy begin excluded from the Extrude Cut feature.

 

This concludes the example.

Related Topics

The CAD Overview